Method for protecting polyphase autotransformer for aircraft, involves controlling values from incoming currents and/or outgoing current in phase of auto-transformer according to comparison result

摘要

The method involves determining value representing homopolar current circulating in a phase (102) according to a value of current representing the operation of another phase and a value from outgoing current of the latter phase. The value representing the homopolar current is compared with a predetermined threshold value (S1) (104) for a predetermined period. The values from incoming currents and/or outgoing current in the phase of the auto-transformer is controlled (106, 108, 110) according to the comparison result. Independent claims are also included for the following: (1) a safety device (2) an aircraft.